CBN grinding wheels

[Tom Bussey]

Stumpy Nubs recommends a 80 and a 360 grit CBN wheel for general reshaping of wood working tools and 180 and 600 grit for Lathe tools. I have that type of a set up, that has both a 80 and a 360 grit CBN wheels on it, over at my shop, which is about one mile from home. I can not afford to heat my shop so it sets idle for the winter months. I tend to do furniture building and the building work benches over there and more lathe work in the winter here at home in the colder months.

Personally I think he is correct on both recordation's but not enough to warrant the cost of the buying both 80- 360 and 180-600 wheels verses buying only the 180 and 600 grit CBN wheels.

And to be truthful I have had no loading up the CBN wheels with the sharpening of chisels. as some would have everyone to believe. One can buy the slick stick to put on the wheels that is supposed to help but I don't personally think it is necessary.

Some of the advantage of a CBN wheel are, they never go out of balance, never go out of round, always stay the same diameter and since the plates are smooth aluminum you can stop the rotation by using your fingers on the sides of the wheel ( same principal as disc brakes on a car.). You can also grind on the side of a CBN wheel if the wheel has grit on the side, which is a no no if using a stone wheel. And lastly it does not produce much heat
so one can grind right up to the edge. And my disclaimer here is it there is always one that has his head other places than on his shoulders.

Some disadvantages, CBN likes hard steel, But it hates soft steel and anything else that would clog up and ordinary wheel. We use a very fine CBN wheel on a surface grinder to grind carbide at work but I didn't pay for that wheel. My personal experience with free hand grinding carbide is with a diamond wheel and using water to cool the diamond plate and tools. I can also guarantee that diamond wheels hate soft steel probably more so than CBN. Also at the cost of the CBN wheel, I am not going to try to grind carbide to find out.

The one one advantage and disadvantage at the same time is, one does not need to guard the CBN wheel but an ordinary grinding wheel does need to be guarded, so having two bench grinder is another expense to be considered. I prefer the wider CBN wheels which do not fit on grinders that have wheel covers on them.

DO I think that CBN wheels are worth the cost? When it comes down to sharpening ,Yes I do.

[Derek Cohen]

Tom, I would not trust “Stumpy Nubs” opinion, if you are looking for user experience. He is a less of a woodworker and more of a performer. I am sure that he has a team feeding him information, and everything is a prop in his “shop”.


CBN wheels are great. I believe that I was among the first to write about them several years ago, possibly the first for flat woodworkers, but they had been known among the turning crowd for some time already.


http://www.inthewoodshop.com/Woodwor...ningSetUp.html


For most hollow grinding of bench chisels and plane blades, you will use a 180 grit. At the time I chose this it was going to replace a Tormek, which grinds at 220. The decision was a good one - I have an 80 grit wheel, but only use it when having a lot of grinding to do. The common grinding is done with a 180. It will lose a smidgeon of bite over several years, but nothing to shout about. Its advantage of 80 grit is that it leaves a smoother edge, which means there is less work to do when honing.


As far as lathe chisels go, these are a different category. Keep in mind that the great majority are M2 steel (the more common high speed steel), while some are M4 (a more durable still PM steel). Both are impervious to heat, unlike the blades used for flat woodworking. Further, most would grind to sharpen off the wheel. Therefore, smoother wheels are indicated. For daily resharpening I would probably go 360 and 600, with 180 used for shaping. Many of the serious turners I know have more than one grinder. My turning is limited to spindles for legs, and 180 is good enough for me as I will finish with a skew chisel or sandpaper.


Regards from Perth


Derek

[John Keeton]

I bought my first CBN 8-9 years ago in a 180 grit to use on my turning tools. It was and remains a great wheel. However, a couple years ago I upgraded my grinder and added a 600 grit. It is now used exclusively for touch up sharpening of lathe tools. It will remove material faster than you might realize. I will use the 180 if reshaping is needed. I don’t use either for flat work blades, but only because of my sharpening methods.

[Frederick Skelly]

Thanks Tom. Appreciate you taking the time to share your experiences and thoughts. I too have a cbn wheel and I really like it.
Fred

[Edward Weber]

I agree with all the above advice and will add, that an 80 grit CBN is an aggressive wheel. IMO unless you need to reshape steel often, it's not necessary.
I have pretty much the same experience as John Keeton wrote in his post.

[Tom Bussey]

Some back ground information. I out grew my shop in the basement and it is cheaper to buy an old building on main street in town an it is to build a two stall garage. And a 2 stall wouldn't have been big enough anyway. I do not use all of my building for a shop but it is a 2 story and I have 3500 SF Ft on the ground floor and 3500 on the second floor. Actually I have a Ball Room up there.. Like I said there is no insulation in the building and I can not afford to heat it.

One of the real problems with my set up, is needing something at home and it is in the shop a mile away. It is more of a problem in the winter time. I try not to have multiples of any thing but some times I just bit the bullet.

I own a 80-360 CBN wheel combination, And it is over in my shop in town. What I have found is the 80 grit wheel is a real hog and material comes off very quickly. I think that the surface left by the wheel is very rough and the edge looks jagged. Maybe it is just me, but I do not like the the finish from the 80 grit, to rough. I do like the finish I get from the 360 grit wheel. To me it is like a cut from a real cheap blade and a sharp Forrest blade, no comparison.

For me I found the 80 grit wheel to course for lathe scrapers. Woodworkers Wonders recommends a 180 grit wheel for lathe scrapers. I haven't tried doing a scraper as of yet. But I did rough in some chisels.

I prefer a flat grind on my lathe skew chisels. And the finish was expectable form the 360 but I feel it could be smoother and sharper so I got the 600 grit wheel. I did find the 360 to be adequate for gouges both bowl and spindle but I thought a 600 would take the edge to the next level.

I did finish of the flat chisel with the 600 grit wheel and it took very little work on the stones to get a sharp and I mead sharp edge on the chisels. It took less time to finish the chisels than when I sharpened them with a 360 wheel.

Okay, What I have found is I really like the 1 1/2 wide wheels better than the one inch wide wheels. i can move the tool all around better. The 180 wheel will not remove the material nearly as fast as the 80. But the time the 180 took was exceptable to me. I haven't tried the 600 on my lathe tools yet but I I bought it because I though it would give me a little sharper edge on my lathe tools than the 360.

I have personal experience with all 4 wheels. I like the 180- 600 grit wheels better. There are gives and takes on all 4 wheels. I just feel the 180- 600 wheels better fit my purposes. And I thought I would pass along what I prefer to use. If you disagree, that is absolutely fine with me

I think I will do some lathe work tomorrow then I will have a better idea how I like the 180 on a scraper and the 600 on the rest of the tools.

As far as Stumpy Nubs goes, I agree with him a lot of the time, But I also don't agree with him. He has some good point a and sometimes I wonder about him but I am sure that is true with all of us.

Happy sharpening.

Tom

[Derek Cohen]

As far as Stumpy Nubs goes, I agree with him a lot of the time, But I also don't agree with him. He has some good point a and sometimes I wonder about him but I am sure that is true with all of us.

Tom, SN is not a person. He is a committee, a spokesperson, a puppet. The workshop is a stage set. This is a business that trades on clicks, being paid by these clicks, and probably doing very nicely. There are many like SN, unfortunately increasingly so on YouTube … all posting simple builds, all the same, copying each other, click baiting ..

Regards from Perth

Derek